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Aluminum or Magnesium?

Hi all! This is my first post on the Miller forum.

I use my Econotig for general hobby welding, and I occasionally use it for my X-ray repair business. One problem that I recently encountered is I was trying to repair a broken metal bracket that holds a rear cover onto a Dental X-ray tube head. From the look and feel of the metal, I was certain that it was cast Aluminum, but I had a heck of a time trying to Tig weld it. The broken section of the bracket is only about 0.25 in wide by 0.125 in think, and about 3 inches long. The metal seems to be very brittle, as it breaks very easily when flexed even a small amount. When trying to Tig weld it, the metal just melts into a very rough looking blob, and will not accept Aluminum filler rod. After many frustrating attempts, I began to wonder if maybe the metal isn't Aluminum, and is rather Magnesium. So, could anyone please tell me how I could test the metal to determine if in fact it is Magnesium instead of Aluminum? BTW - I'm using pure Argon, with 1/16 inch Thoriated Tungsten.

Thanks!

Some people are like a Slinky... They aren't much good for anything, but they bring a smile to your face when you shove them down a flight of stairs.

Back in the 60's we used to play with the different metals in science class. Our teacher would sneak in the back room and pull out his flask on occassion, we didnt see him for 15 minutes so we would play with different things, mercury was fun and we almost burnt the lab up. Yes, science was fun

I believe you may want to consider some other kind of tungsten since i have heard this type is very harmful to your health without proper ventalation.

I believe you are referring to the fact that Thorium is slightly radioactive, which is very bad to breath into your lungs. I Tig weld with very good ventilation, even when using pure Tungsten. Any metallic vapors are bad to inhale, and some are much worse than others. The Miller site has lots of good articles about welding safty, which include plenty of warnings about smoke and fumes given off by the welding process.

Some people are like a Slinky... They aren't much good for anything, but they bring a smile to your face when you shove them down a flight of stairs.

Back in the 60's we used to play with the different metals in science class. Our teacher would sneak in the back room and pull out his flask on occassion, we didnt see him for 15 minutes so we would play with different things, mercury was fun and we almost burnt the lab up. Yes, science was fun

What else is there besides welding and riding??? Hmmmm..... I can think of one thing, but I might get kicked off this forum if I mentioned it!

Some people are like a Slinky... They aren't much good for anything, but they bring a smile to your face when you shove them down a flight of stairs.

Magnesium welds fine. You need magnesium filler for it though. Don't leave any grindings or shavings laying around, those WILL burn!

I agree. I repaired three (3) vintage go kart magnesium wheels yesterday. I've also done BBS (BMW) & Ferrari wheels. The BBS was a joy to weld on, quite free of contaminates. Ferrari and old McCulloch wheels are more challenging to get a porous-free interface of old & new.

The filler rod is expensive (last purchase $92/Lb.) but a pound goes a long way! Trick is to find a supplier willing to sell less than 10 Lbs!

I saved all the shavings from turning a repair (lathe swarf) in a paper bag and threw it on a bonfire. VERY bright white, but quickly burnt itself out. Don't try that in your shop! So yes, keep the area clean from shavings and grinding dust.

Magnesium oxidizes very quickly, so any repairs need to be cleaned back to bare metal. I usually use a carbide "tree" in a die-grinder for this. It helps to direct the chips away from your clothing.